Jesse is 100% correct; get whatever you can get. As Jesse also stated, it is VERY difficult to get a job at 15. I applied to three places when I was 15, and would call, and they said they aren't hiring 15 year olds at the moment. Luckily, my neighbor let me work at her day care over that summer at 15, and THANKFULLY my last day at my neighbor's day care was my first day at my first "real job." It was at fast food, which I tried so hard to avoid. While I did not like it, I still had to go in with an open mind, and I did. When I left, I was making $2.50 MORE than I was when I started. Hard work pays off.
Basically, Jesse hit it right on the head. Persistence pays off. I waited FOUR months for the job I have now. I kept calling until they said they would call me back when they had an opening.